Microbiomes and infectious disease

Abstract This chapter explores how the microbiome may influence the susceptibility of animals and plants to infectious diseases. Certain resident microorganisms can synthesize antimicrobial products that specifically target pathogens, while others release compounds that modulate the activity of the host immune system. These effects are most clearly demonstrated for the gut microorganisms of animals, but members of the skin microbiome are also protective, promoting wound healing; and the microbial communities associated with plant roots can defend plants against fungal diseases. Under certain circumstances, however, the resident microbiome can exacerbate infectious diseases, notably some viral infections of the gut. This chapter also considers how the microbiome in insects can affect the capacity of the insect to vector disease agents. Members of the gut microbiome and an internal bacterium called Wolbachia can suppress the capacity of mosquitoes to transmit the virus that causes dengue fever and the agent of malaria.